The basic process
Cloning is simply making genetic copies. Gardeners clone when they take cuttings; identical twins are natural clones, and frogs were first cloned by scientists working to establish the events of early embryonic development in vertebrates in 1952. Cattle breeders have been producing clones by splitting embryos for over 20 years. But when on 27th February 1997 the news broke of the birth of Dolly the cloned sheep, there was tremendous media interest, because this was the first time that a mammal had been cloned.
This picture shows Dolly with her birth, but not genetic mother, and the diagram right explains how she was created:
You can read more detail about this here
Cloning: the possibilities